3家石化企业噪声作业人员听力损失风险评估

Risk assessment of hearing loss of noise workers in three petrochemical enterprises

目的对石油化工企业噪声所致作业人员听力损失的风险进行评估。方法选取3家石油化工企业的噪声作业人员为研究对象,测量研究对象的40 h等效连续A声级(L_(EX,W)),并调查其职业史,开展纯音气导听阈测试,采用ISO 1999:2013模型,计算各岗位听阈级变化、听力损失风险,并与纯音气导听阈测试结果进行比较分析。结果各岗位L_(EX,W)中位数为79.8~85.0 dB(A),除石脑油加工操作工为79.8 dB(A)外,其余岗位L_(EX,W)均>80 dB(A)。纯音听阈测试结果显示,噪声作业人员高频听力损失患病率为12.8%;按照L_(EX,W)最大值进行噪声作业分级显示,除化工部苯乙烯-干气联合装置外操工为极重危害,化工部其余岗位和公用工程的全部岗位均为轻、中度危害,62.5%炼油部的外操工为重、极重危害。采用ISO 1999:2013评估结果显示,常减压蒸馏、制氢装置外操和电气系统电工发生高频听力损失风险较高;不同岗位的男性工人实测噪声致永久性听阈位移值(noise-induced pernament threshold shift,NIPTS)中位数高于ISO 1999 NIPTS中位数预测值(P<0.01),且80%以上岗位的预测值较实测值低10 dB以上。结论该3家石化企业噪声作业工人的噪声暴露致听力损失的风险较高。

OBJECTIVE To evaluate the risk of noise induced hearing loss among workers in petrochemical enterprises.METHODS Number of workers exposed to noise were recruited from three petrochemical enterprises. The noise exposure level(L_(EX,W)) of the research objects was measured, their occupational history was investigated, and the audiometric testing was carried out. The ISO 1999:2013 model was used to calculate the change of hearing threshold level and the risk of hearing loss in each post, and compared the result of model with the result of the audiometric testing.RESULTS The median of L_(EX,W)is range from 79.8 to 85.0 dB(A). L_(EX,W)among all posts were greater than 80 dB(A) except naphtha processing operators. The result of pure tone hearing threshold test showed that the prevalence of high-frequency hearing loss among workers exposed to noise was 12.8%. According to the classification of noise operation according to the maximum value of L_(EX,W), the operator for styrene dry gas combined unit is the only post that is extremely dangerous in the department of chemical, the other posts in the department of chemical and all posts in the department of public works are exposed to light and medium noise hazards, and 62.5% the external operators of the oil refining department are under heavy and extremely hazardous. According to the evaluation result of ISO 1999:2013, the risk of high-frequency hearing loss among workers in crude distillation unit, hydrogen production unit and the electricians of electrical system is high. The measured median of noise-induced pernament threshold shift(NIPTS) among male workers in different workstation was higher than the predicted median of NIPTS of ISO 1999, and the difference was statistically significant(P<0.01), and the predicted values for four-fifths of positions were more than 10 dB lower than the measured value.CONCLUSION The risk of noise induced hearing loss of workers in petrochemical enterprises is high.